This disclosure relates to a gas turbine engine component, such as an airfoil. More particularly, the disclosure relates to a configuration of cooling holes.
Gas turbine engines typically include a compressor section, a combustor section and a turbine section. During operation, air is pressurized in the compressor section and is mixed with fuel and burned in the combustor section to generate hot combustion gases. The hot combustion gases are communicated through the turbine section, which extracts energy from the hot combustion gases to power the compressor section and other gas turbine engine loads.
Both the compressor and turbine sections may include alternating series of rotating blades and stationary vanes that extend into the core flow path of the gas turbine engine. For example, in the turbine section, turbine blades rotate and extract energy from the hot combustion gases that are communicated along the core flow path of the gas turbine engine. The turbine vanes, which generally do not rotate, guide the airflow and prepare it for the next set of blades.
Gas path temperatures are well above the melting point of hot section components, necessitating cooling component for adequate durability. Many blades and vanes, blade outer air seals, turbine platforms, and other components include internal cooling passages. Some of the cooling passages may communicate cooling flow from the cooling passage through cooling holes to an exterior surface.
The film cooling holes may be formed according to a wide variety of configurations, such as slots, cylindrical holes and holes of shaped geometries. One configuration utilizes a dumbbell or dog bone shaped hole in which the intersection of the holes is enlarged to widen and smooth the aperture at the intersection of the holes. Another example hole configuration utilizes intersecting holes in which one side of the intersection is enlarged to provide a flat surface that is tangential to each of the holes. Both of these hole configurations are rather complicated to form and may be beyond the practical or economical limits of widely used cooling hole forming techniques.